Signaling system for railways.



H. W. GRIPFlN. SIGNALING SYSTEM FOR RAILWAYS.

APPLICATION TILED SEPT. 21, 1908.

1,000,401 Patented Aug. 15, 1911. 3 SHEETS-SHEET 1.

J m 5 m d n? a p H. W. GRIFFIN.

SIGNALING SYSTEM FOR RAILWAYS.

APPLICATION FILED SEPT. 21, 1908.

1,000,401 Patented Aug. 15, 1911.

3 SHEETSSHEET 2.

. FZ/g: J

I l D Fig: 6.

l d lhfi Fig.6. 72

Z 65 [Men/Z07".- L 71/ S. 1 0 7.

H.- W. GRIFFIN. SIGNALING SYSTEM FOR RAILWAYS.

APPLIGATION FILED SEPT. 21, 1908.

' Patented Aug. 15, 1911.

w g/ g m U y TE STATES PATENT ornron.

HENRY GRIFFIN, OF NEW YORK, N. Y., ASSIGNOR TO THE UNION SWITCH & SIGNALCOMPANY, OF SWISSVALE, PENNSYLVANIA, A CORPORATION OF PENNSYLVANIA.

SIGNALING SYSTEM FOR RAILWAYS.

Specification of Letters Patent.

Patented Aug. 15, 1911.

Application filed September 21, 1908. Serial No. 454,066.

4 To all whom it may concern:

Be it known that I, HENRY W. GRIFFIN, a citizen of the United States,residing in the borough of Manhattan, city, county, and State of NewYork, have invented certain new and useful Improvements in SignalingSystems for Railways, of which the following is a specification. I

My invention relates to circuits for single track switch indicators, theobject of the invention being to employ a circuit, including aninterlocking relay, which will operate to clear the indicator undercertain conditions for one direction of traflic and set it to danger forthe opposite direction.

I will describe a switch indicator circuit embodying my invention andthen point out the novel features in claims.

In the accompanying drawings, Figure 1 is a diagrammaticview indicatingthe general way in which single track switch indicators are at presentcontrolled. Figs. 2, 3, 4, 5, 6, 7 and 8 are diagrammatic viewsillustrating my invention and showing various parts thereof in differentpositions under different track conditions. Figs. 9

and 10 are diagrammatic views illustrating modifications.

Switch indicators, as installed at present on single track roads, inconnection with automatic signals, are controlled by trains I on acertain amount of track circuit, the

limit of this control bearing a definite relation to the signalsprotecting a switch, and such control being effected by trains runningin either or both directions.

Referring to Fig. l, the switch G is protected by the signals 1 and 4,and in order to prevent collisions due to a train leaving a siding viathe switch G, the switch indicator is controlled beyond the signalsprotecting the switch, as for example at E and F. Should the switchindicator 'be controlled -only by the track between signals 1 and 4,

train leaving the main line for the siding. It will also be understoodthat the throwing of a switch from the main line position at once setsall the signals leading over or protecting the switch to danger. Underthese conditions, therefore, a train bound either from E to F or from Fto E would hold the indicator for the switch G at danger until the rearend of such train had endisregarded.

Assuming a train to be on the siding and desirous of entering the mainline by way of the switch G, and a train should enter the section at Emoving toward F, the switch indicator would, of course, be set to dangerand a proper observance of the indicator would require the siding trainto wait until the rear of the main line train had passed F, when theindicator would go to safety. This, of course, means delay, andfrequently when the rear of the main line train passes the switch G, thesidingjrain will enter the main line against the danger signal by theswitch indicator and sometimes another train may be followin the firsttrain on the main line and a col ision is therefore rendered possible.

The arrangement of the signals as shown is not the standard one and inmany cases, the signal 2 would not be located so that the crew of thesiding train would be able to know the condition of the track between Eand G.

My invention is designed to obviate the delay referred to and enable theswitch indicator to give a clear signal to the siding train after themain line train has passed the switch G on its way to F provided that noother train has entered the section at E on its way to the switch G.

In Figs. 2, 3, 4, 5, G, 7 and S the block signals and their connectionsare omitted, as the connections between the signal system and the switchwould be as usual and may be readily understood.

In Fig. 2 I have indicated a switch G and two insulated track sectionsAB and C.D forming part of the main line, and between these two.sections, for convenience of illustrating the invention, I have shownashort section -B-C, which is a dead section, or in other words, does notoperate as a track circuit, and the switch enters the main line at thissection. This dead section should be shorter than the shortest wheelbase of the cars intended for use on the road. It will be understood,however, that other forms of switch insulation may be employed in whicha dead section is not employed, in which case the track sections are A-Band B-D.

The section AB is provided with a track battery I) and the section CD isalso provided with a track battery d, and from the rails ponstitutingthe section AB, circuit wires 12-13 lead to one .coil N of a hook orother form of interlocking relay, and from the track rails comprisingthe section 6-D, circuit wires 14 and 15 lead to the other coil M ofsaid interlocking relay.

The switch indicator is indicated by O and the motor for operating theindicator derives its current from a battery P and the circuit wires ofthe motor are connected to the hooks n and m respectively. It is ofcourse understood that no current canpass directly from the hook m tothe hook n, and the hook m is therefore provided with a contact 16 andthe hook n with a contact 17, which contacts are adapted to engagecontacts on a bridge or loop 18.

As shown in Fig. 2, the parts are supposed to be in normal position withthe contacts 16 and 17 both in engagement with the bridge 18 and thecircuit through the indicator motor closed to move said indicator toclear position, the contacts 16 and 17 being held in engagement with thebridge on account of the coils M N being both energized by the trackbatteries.

Assuming now that a train is on thesiding and waiting to enter the maintrack through the switch G and proceed toward A and that a train is alsoon the section C-D proceeding toward A, as shown in Fig. 3,

the coil M will be denergized and the hook m will move to disengage itscontact 16 from the bridge 18 and the switch indicator will move todanger position. As the train on the main line proceeds and overlaps thedead section BC, standing partly on Section A-B and partly on sectionC-D, the coil N will also. be deenergized and the hook n will move todisengage its contact 17 from the bridge 18 as indicated in Fig. 4. Asthe train proceeds on the main line, and passes entirely off the section(3-1), the coil M will be again energized and will move the contact 16into engagement with the bridge 18, but the motor circuit will still beopen between 17 and 18 as indicated in Fig. 5, but as soon as the mainline train has passed entirely 011' the section A-B, the coil N willagain be energized and close the circuit at 17 and 18,

.which will complete the circuit for the motor which operates the switchindicator and the parts will then be restored to the position indicatedin Fig. 2, thus giving a clear signal to the siding train, which canthen proceed on its way toward A.

Referring now to Fig. 6 and assuming that a train has entered thesection AB and is proceeding toward D with a train on the siding, thecoil N will be deenergized and the indicator circuit will be broken at1718, and as soon as the main line train passes onto the section CD, orin other words overlaps the dead section BC, standing partly on sectionAB and partly on section CD, the coil M will also be deenergized but,under these conditions, the hook, m will-be able to have only a limitedmovement before it will be stopped by the hook n as shown in Fig. 7 andsuch movement will not be sufiicient to break the contact at 1618. Assoon, therefore, as the train on the main line clears the section AB,the coil N will again be energized and will move its hook n and causeits contact 17'to engage the bridge 18 and the circuit through theindicator motor will thereupon .be closed and the switch indicator willbe moved to clear position and ,the siding train can at once proceedtoward A without waiting until the main line train has cleared thesection C-D. This is of course, assuming that another train has notentered the section AB in the meantime, for if another train had enteredthe section A-B, the indicator circuit will be again broken at 1718.

It will of course be understood that for the above actions to takeplace, the interlocking relay must be properly adjusted.

This adjustment maybe accomplished in various ways, and in the drawingsI have shown it as follows: Hook m is shorter than hook n, so that whencoil M is deenergized first, and then coil N is deenergized, asindicated in Figs. 3 and 4, hook n is permitted to move far enough toopen its contact 1718. When, however, coil N is deenergized first,followed by coil M, as indicated in Figs. 6 and 7, hook m is preventedby the end of hook n from moving far enough to open the contact 16-18.Referring now to Fig. 8. when coil N is again energized the flexibilityof book n permits contact 1718 to close, but hook m is held from openingcontact 1618, even though coil M remains deenergized.

' Referring now to Fig. 9, I here show a modification of the apparatusshown in Figs. 2 to 8. In this case, a circuit controller H operativelyconnected with the switch is included in the circuit for coil M of theinterlocking relay. The circuit controller H comprises a movable contactmember adapted to engage with two stationary contacts member is inengagement with contact L,

but during a movement of the switch in either direction the movablemember momentarily engages with contact K.

Assume that a train U enters section AB on its way to the switch. Coil Nis then deenergized and hook n moves to open contacts 1718. Assume thatanother train V now enters section CD also proceeding toward the switch.Coil'M will then be deenergized, but hook m will be prevented by hook atfrom inoving far enough to open contact- 1618, and the parts of therelay would then be asindicated in Figs. 7 and 9. It now train U entersswitch G, coil N would become energized and would close contact 1718,and with the equipment shown in Figs. 2 to 8-, the indicator would becaused to give a clear signal, the positions of the parts of the relaybeing as shown in Fig. 8. Thetrain on the siding might then enter themain line while train V approaches the'switch, and a collision would berendered possible. With the equipment shown in Fig. 9, however, when theswitch G is moved back to the main line position after train U hasentered the siding, coil M is momen tarily energized from battery 15,closing hook m and thereby freeing this hook from hook n. hen thismovement of the switch is completed, coil M is again connected directlywith the track rails of section C-D, and since these rails are occupiedby a train V, coil M is deenergized, hook m opens and breaks theindicator circuit at 1618, thereby causing the. indicator to give'adanger signal.

In Fig. 10 is shown a further modification in which the coils M andN are.not directly connected to the track circuits. In this figure, the partsare in normal position when no train is on the sections A B and CD. In

this case, the coil N derives its current. from section AB magnet 33will be decnergized and signal 30 will go to danger and break thecircuit for coil N at the controller 25.

Coil M derives its current from a battery m through a circuit includingwires 14* and 15 a train moves and a controller '34 which is operated bya magnet 35 which derives current from track battery d. When a train ison the section CD magnet 35 will be denergizedand circuit for coil Mwill be broken.

The coils M and N may of course be otherwise controlled as for exampleby the same track relays that control the block signals, or any othersignals.

Other relays than the hook type may be used suchas those which havetheir armatures drop on insulation under. one condition and on aconductor under other conditions. Other types have their armatures dropon stops thus preventing contact under certain conditions.

Having'thus described my invention, I claim:

1. In combination with a railway track,

a switch, a switch indicator for the switch,

insulated main track sections extending in each direction from theswitch, an interlocking relay for controlling the movement of the switchindicator, and means controlled by the movement of a train over theinsulated sections for operating the relay to clear the indicator when atrain moves past it in one direction and to'leave it at dan er when pastit in the opposite direction.

2. In combination with a railway track, a switch, a switch indicator forthe switch, insulated main track sections extending in each directionfrom the switch, a motor for the switch indicator, an interlocking relaycontrolling the motor circuit, and circuits controlled by the movementof a train over said sections to operate said relay to clear theindicator when a train moves past it in one direction and to leave it atdanger when a train moves past it in the opposite direction.

3. In combination with a railway track, a switch, a switch indicator fortheswitch, insulated main track sections extending in each directionfrom the switch, a motor for the indicator, an interlocking relaycontrolling the motor circuit, circuits connecting the interlockingrelay and the insulated track sections and controlled by the movement ofa train over said sections to clear the indicator when a train moves inone direction past the switch and leave it at danger when a train movespast it in the opposite direction. a

4. In combination with a railway track, a switch, a switch indicator forthe switch, an insulated main track section extending in each directionfrom the switch, an interlocking relay having two coils for controllingthe movement of the indicator, and means interposed between therespective insulate'd sections and the respective coils and controlledby the movement of a train over both sections for operating said relayto clear the indicator when a train moves past it in one direction, andto'leave it at danger when a train moves past it in the oppositedirection.

5. In combination with a railway switch,,

the main track for the operation of the relay. I

6. In combination with a railway track, a switch leading from saidtrack, a switch indicator for the switch, an interlocking relay for Erecentral of the switch. indicator and comprising two magnet windings,insulated sections of the said track extending in each direction'fromthe switch, a track circuit for each. of the track sections, eachcircuit comprising a source of current and a magnetwinding of theinterlocking relay.

7. In combination with a railway track, a switch leading from saidtrack, a switch indicator for the switch, an interlocking relay for thecontrol of the switch indicator and comprising two ma et windings,insulated sections of the said track extending in each direction fromthe switch, a track circuit for each of the track sections, each circuitcomprising a source of current and a magnet winding of the interlockingrelay,

and a circuit controlled by the interlocking lay for the control of theswitch indicator and comprising two magnet windings, insulated sectionsof the said track extending in each direction from the switch, a trackcircuit for each. of the track sections, each circuit comprising asource of current. and a magnet winding of theinterlocking relay,

an additional source of current, and a clrcuit controller operatiyelyconnected with the switch and adapted to disconnect oneof the magnetwindings from its track circ it and connect the sald magnet winding withthe additional sourceof current.

Intestimony whereof I have signed m name to this specification in thepresence of two subscribing witnesses.

t HENRY W. GRIFFIN.

Witnesses:

M. L. KIRTLAND, W. F. WOOD.

